This application claims the priority of German patent document 102 23 655.0, filed May 28, 2002 (PCT International Application No.: PCT/DE03/01568, filed May 15, 2003), the disclosure of which is expressly incorporated by reference herein.
The invention concerns an arrangement for axially and radially fixing the guide vanes of a guide vane ring of a gas turbine.
Gas turbine configurations are known in which the stator of the gas turbine does not form an integral unit, but has critical connecting and support points with reference to a gap that must be maintained. Fixing arrangements must be provided, which take into consideration the temperature gradients that occur between the turbine housing and the guide baffle ring, the realization of which can cause considerable difficulties. As a consequence of confined space conditions and poor accessibility, the milling work on the stop surface located on the turbine housing for providing the required fixing arrangements can be achieved only with great effort. This applies not only in the case of the first installation, but also to repair and restoration work as a consequence of wear during the operation of these gas turbines.
One object of the present invention is to provide a new configuration for the means for fixing the guide vanes of a guide vane ring of a gas turbine.
This and other objects and advantages are achieved by the fixing arrangement according to the invention, in which the milling work required to establish the necessary proportions and the gap is moved to the shell rings and holding pieces that are separated from the turbine housing via new form-fitting locking elements. The latter are assigned to the end of the guide vanes of the guide vane lattice and are farthest from the hub, with their contact surfaces, which determine the play and the position of the guide vanes; and the shell rings and holding pieces are consequently better accessible for machining and for repair and restoration work.
The guide vanes can also be joined by means of new locking elements before installation in the turbine to form a module, thereby providing a simple partner interface and considerably simplifying assembly. Moreover, the new locking elements make possible in particular an almost play-free fixing of the guide vane rings directly on the spoke centering device, while eliminating the annular seals which were previously necessary. Arrangement of the support points on the shell rings decouples the spoke centering device from the turbine housing, thereby preventing deformations of the turbine housing that occur during the operation of the gas turbine from directly influencing the spoke centering device. Finally, the usual casting on of the mounting points of the so-called “outer air seals” can be eliminated with the new locking elements.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.